Various forms of long-term storage in computer systems include, other than electromechanical hard disks, non-volatile storage rooted in semiconductor or other memory technology. NOT-AND (NAND) flash memory is one form of non-volatile memory used in solid-state storage devices. In a common configuration of flash memory, the memory cells are arranged in typical row and column fashion with circuitry for accessing individual cells. The data store elements (e.g. transistors) of those cells are configured to hold two logical states in the case of Single Level Cell (SLC) or more than two logical states in the case of Multi Level Cell (MLC).
The flash memory is block-based storage and can require a block to be erased before being rewritten. Other commands cannot be performed while the erase operation is being performed. This can lead to longer command latency for the other commands while they wait for the erase operation to complete. In addition, because the duration of the erase operations can increase as the flash memory ages, the command latency can increase over time.
Thus, a need still remains for better data storage devices that can optimize command latency. In view of the ever-increasing commercial competitive pressures, along with growing consumer expectations and the diminishing opportunities for meaningful product differentiation in the marketplace, it is important to find answers for these problems. Additionally, the need to reduce costs, improve efficiencies and performance, and meet competitive pressures adds an even greater urgency to the critical necessity for finding answers to these problems.
Prior developments have long sought but not found optimal solutions to these problems. Hence, there remains a need that has long eluded those skilled in the art.